A natural collapse method coupled with subsequent filling.

Abstract

This invention provides a natural caving method coupled with subsequent backfilling. By optimizing the bottom structure and construction procedures of the traditional natural caving method, it combines the advantages of both methods, avoiding the need for bottom drilling, charging, and blasting. This effectively solves the problems of large workload, cumbersome procedures, poor results, unstable bottom structure, and low production capacity during the infrastructure construction period associated with the natural caving method. This method provides technical support for simplifying bottom drilling and other processes in the natural caving method, improving bottom structure stability, and increasing production capacity during the infrastructure construction period. It is characterized by wide applicability, safety, and high efficiency.

Description

Technical Field

[0001] This invention relates to the field of mining, and more particularly to a natural caving method coupled with a subsequent backfilling method. Background Technology

[0002] Natural caving has advantages such as low cost and high production capacity, and its application in metal mines both domestically and internationally has become increasingly widespread in recent years. However, it requires the construction of numerous bottom-running tunnels and fan-shaped boreholes for bottom-running blasting, making the process complex and inherently unsafe. The bottom structure, as the main production area, is typically only about 20 meters thick, and the ore within it contains numerous primary and secondary joints, which significantly impact its stability. Natural caving also involves long initial construction periods and substantial capital investment, with only partial by-product production during this phase, resulting in a low return on investment. Therefore, traditional natural caving methods still have considerable room for improvement in terms of technology and safety.

[0003] The mining method disclosed in CN104533415B, "A Mining Method Coupled with Stage Forced Caving and Natural Caving," requires the excavation of numerous roadways in the bottom structure, which is detrimental to its stability. Furthermore, it necessitates the use of a large amount of explosives for forced blasting, resulting in a complex process and poor safety. The bottom ore-receiving structure and mining method disclosed in CN113062741A still requires the arrangement of numerous bottom-pull roadways and the use of fan-shaped blast holes for bottom-pulling. Moreover, the vertical difference between the bottom-pulling level and the ore-exiting level is only 18–25 m, resulting in a thin bottom structure and poor stability. The bottom structure disclosed in CN219932153U, "A Bottom Structure for Natural Caving," like traditional natural caving methods, requires the arrangement of bottom-pulling levels, necessitating extensive bottom-pulling work before caving, making the workload large and complex.

[0004] In summary, the traditional natural caving method faces problems such as large-scale bottom-laying engineering, unstable bottom structure, and low return on investment during the infrastructure construction period, which have long limited the operation of natural caving mines and urgently need to be addressed. Summary of the Invention

[0005] The main technical problem to be solved by this invention is to provide a natural caving method coupled with the subsequent backfilling method. By combining the subsequent backfilling method and the natural caving method mining process, the excavation of a large number of bottom roadways and bottom fan-shaped holes is avoided, the process is simplified and the work safety is improved; the thickness of the bottom structure is increased, and the stability of the bottom structure is improved; a large amount of ore is recovered earlier, and the return on investment during the infrastructure period is improved.

[0006] To address the aforementioned technical problems, this invention provides a natural collapse method coupled with a subsequent filling method, comprising the following steps:

[0007] Step 1: Construct rock drilling tunnels, ore loading tunnels, and ore exit routes;

[0008] Step 2: Construct blasting holes from the rock drilling tunnel toward the mine pillar;

[0009] Step 3: Explosive charging and blasting in the blasting holes to complete the pillar mining from the middle of the ore body outwards to both sides;

[0010] Step 4: Fill the empty area after the pillar is mined out from the rock drilling roadway with ultra-high strength filling material. The strength of the filling material is not lower than that of the original rock. When filling, leave an 8-10m height at the top of the empty area unfilled. The loading roadway and ore exit roadway in the middle of the production section can be filled with the same method as the roadway left along the goaf.

[0011] Step 5: After the ultra-high strength backfill body has been cured, drill holes upwards from the ore-producing level to mine the remaining stopes, starting from the footwall side of the ore body;

[0012] Step Six: Normal caving production is carried out in the area where the stope and pillars have been recovered. The above steps are repeated in the remaining areas to complete normal caving production.

[0013] In a preferred embodiment: the bottom structure is divided into mine pillars, and the height is 50-60m.

[0014] In a preferred embodiment: the pillar formed after filling serves as the ore-gathering pillar of the subsequent natural caving method, and the void formed by stope mining serves as the ore-gathering trough.

[0015] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0016] This invention optimizes the bottom structure and construction procedures of the traditional natural caving method, combining the advantages of both the open-field backfilling method and the natural caving method. It avoids the need for bottom drilling, charging, and blasting, effectively solving the problems of large workload, cumbersome procedures, poor results, unstable bottom structure, and low production capacity during the construction period associated with the natural caving method. This method provides technical support for simplifying the bottom caving process in the natural caving method, improving bottom structure stability, and increasing production capacity during the construction period. It is characterized by wide applicability, safety, and high efficiency.

[0017] This invention offers safe and reliable construction, a simple process, and good economic benefits. By optimizing the structure and construction procedures of the traditional natural caving method, it combines the advantages of both open-pit backfilling and natural caving mining methods. This simplifies the process steps, eliminating the need for bottom drilling, charging, and blasting, effectively solving problems such as large-scale bottom drilling, cumbersome procedures, and construction hazards. It also increases the thickness of the bottom structure, improving its stability. Furthermore, it allows for the recovery of a large amount of ore during the mine's infrastructure construction period, increasing the return on investment during this phase. Attached Figure Description

[0018] Figure 1 A schematic diagram showing the ore extraction level, drilling level, and pillar recovery.

[0019] Figure 2 for Figure 1 Sectional view at position II;

[0020] Figure 3 for Figure 1 Sectional view at position I II I;

[0021] Figure 4 Schematic diagram of pillar filling and stope recovery;

[0022] Figure 5 for Figure 4 Sectional view at position II;

[0023] Figure 6 for Figure 4 Sectional view at position I II I;

[0024] Figure 7 A schematic diagram illustrating the natural caving of ore after the completion of stope mining;

[0025] Figure 8 for Figure 7 Sectional view at position II;

[0026] Figure 9 for Figure 7 Sectional view at position I II I;

[0027] Among them: 1. Lower footwall roadway along the vein; 2. Ore extraction through the vein; 3. Ore loading access road; 4. Upper footwall roadway along the vein; 5. Upper footwall ramp; 6. Lower footwall ramp; 7. Drilling roadway; 8. Drilling communication box; 9. Stope; 10. Pillar; 11. Blasting borehole; 12. Mine to be caved; 13. Existing caved ore; 14. Ultra-high strength backfill. Detailed Implementation

[0028] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0029] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed", "equipped", "sleeved / connected", "connected", etc., should be interpreted broadly. For example, "connection" can be a wall-mounted connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0031] This implementation example involves a copper-producing metal mine. The planned mining operation involves extracting an ore body at elevations from -210m to -450m. The ore body has a strike length of approximately 1450m, an average thickness of approximately 360m, a dip angle of 45° to 55°, and an ore grade of approximately 0.56%. The ore's caving capability is moderately cavable to difficult to cavitate. Natural caving mining is employed. This invention, by combining subsequent backfilling and natural caving techniques, avoids the need for extensive excavation of bottom tunnels and bottom fan-shaped boreholes, simplifying the process and improving operational safety. It also increases the thickness of the bottom structure, enhancing its stability; and allows for earlier recovery of a significant portion of the ore, improving the return on investment during the infrastructure phase.

[0032] refer to Figures 1-9 This embodiment provides a natural collapse method coupled with a subsequent filling method, including the following steps:

[0033] Step 1: Construct rock drilling tunnels, ore loading tunnels, and ore extraction access roads, such as... Figure 1 As shown;

[0034] Step Two: Construct the large borehole from the rock drilling tunnel towards the pillar, such as... Figure 1 As shown;

[0035] Step 3: Large-hole blasting, starting from the middle of the ore body and proceeding outwards to complete pillar mining, such as... Figure 1 and Figure 4 As shown;

[0036] Step Four: Fill the empty areas after pillar mining from the rock drilling roadway with ultra-high strength backfill material (the strength of the backfill material should not be lower than that of the original rock). Leave an 8-10m gap at the top of the empty area unfilled during backfilling. The loading roadway and ore exit roadway in the production section can be filled using the same method as the gob-side roadway retention method. This saves backfill material and avoids the need for subsequent excavation of the ultra-high strength backfill material. Figure 2 As shown;

[0037] Step 5: After the ultra-high strength backfill body has completed its curing period, the remaining stopes need to be mined by drilling upwards from the ore-producing level, starting from the footwall side of the ore body. Figure 4 As shown, the 8-10m space reserved for filling after the pillar is mined and the cavity formed after the stope is mined provide conditions for the natural collapse of the ore.

[0038] Step Six: In areas where stope and pillar recovery is complete, normal caving production continues. In other areas, the above steps are repeated until normal caving production is achieved. Figure 5 As shown.

[0039] Furthermore, the natural caving method coupled with the subsequent filling method is characterized by the fact that it does not require the construction of bottom-drilling tunnels and bottom-drilling blasting, but only the construction of rock drilling tunnels, thus saving a large amount of rock drilling and blasting work.

[0040] Furthermore, the natural caving method coupled with subsequent filling is characterized in that: the bottom structure is divided into ore chambers and pillars with a height of approximately 50-60m, which increases the thickness of the bottom structure and improves its stability.

[0041] The natural caving method coupled with subsequent backfilling is characterized by: first constructing blasting holes from the rock drilling roadway towards the pillars, then backfilling the pillars from the middle of the ore body to both sides, and then filling the goaf area of ​​the pillars with ultra-high strength backfill material. During the backfilling, a height of 8-10m is reserved at the top of the goaf without filling. After the curing period of the ultra-high strength backfill material, holes are drilled upwards from the ore extraction level to return to the stope. The stope does not need to be backfilled.

[0042] The natural caving method coupled with subsequent filling method is characterized in that: the pillar formed after filling can be used as the accumulation trough pillar of the subsequent natural caving method, and the void formed by stope mining can be used as the accumulation trough.

[0043] The natural caving method coupled with subsequent filling method is characterized by the ability to recover a large amount of ore during the infrastructure construction period of a natural caving mine, thereby improving the return on investment during the infrastructure construction period.

[0044] The above description is merely a preferred embodiment of the present invention and is not intended to limit the patent scope of the present invention. Any technically equivalent modifications made based on the content of this specification shall fall within the protection scope of the present invention.

Claims

1. A natural collapse method coupled with a subsequent filling method, characterized in that... Includes the following steps: Step 1: Construct rock drilling tunnels, ore loading tunnels, and ore exit routes; Step 2: Construct blasting holes from the rock drilling tunnel toward the mine pillar; Step 3: Explosive charging and blasting in the blasting holes to complete the pillar mining from the middle of the ore body outwards to both sides; Step 4: Fill the empty area after the pillar is mined out from the rock drilling roadway with ultra-high strength filling material. The strength of the filling material is not lower than that of the original rock. When filling, leave an 8-10m height at the top of the empty area unfilled. The loading roadway and ore exit roadway in the middle of the production section can be filled with the same method as the roadway left along the goaf. Step 5: After the ultra-high strength backfill body has been cured, drill holes upwards from the ore-producing level to mine the remaining stopes, starting from the footwall side of the ore body; Step Six: Normal caving production is carried out in the area where the stope and pillars have been recovered. The above steps are repeated in the remaining areas to complete normal caving production.

2. The natural collapse method coupled with subsequent filling method according to claim 1, characterized in that: The bottom structure consists of ore chambers and pillars, with a height of 50-60m.

3. The natural collapse method coupled with subsequent filling method according to claim 1, characterized in that: The pillars formed after filling serve as the pillars for the later natural caving method, and the voids formed by stope mining serve as the ore pools.

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